我厂几年来由于全面使用和不断总结再使用铸钢件水玻璃砂造型,使水玻璃砂铸件在质量上、生产效率上以及作业周期和成本等方面均收到了显著的效果.但唯有旧砂回用问题长期未能得到合理解决,致使大量的旧砂团白白扔掉.对我们铸造部门来讲,这是一个极为痛心的浪费.针对这一问题,我们曾利用机械粉碎法回收旧砂.这种旧砂几年来在生产中试用过多次,而每次都失败了.至于失败的原因,我们认为是:(1)旧砂中的碱度不断地增加,其中主要是Na_2CO_3或NaHCO_3等.在常温混入配制好的水玻璃砂里,使砂粒与砂粒间的水玻璃硅胶粘合能力大大减弱.它在水玻璃砂中是一个隔离物质,又是一种吸 I plant a few years due to the full use of and continue to summarize the re-use steel castings made of sodium silicate, sodium silicate sand castings in quality, production efficiency and operating cycle and cost, etc. have received significant results, but only the old Sand reuse problem has not been properly resolved for a long time, resulting in a large number of old sand thrown away. For our foundry sector, this is a very sad waste. In response to this problem, we have used mechanical crushing recovery of old sand The old sand has been tried many times in production over the years and failed each time, and for reasons of failure, we think it is: (1) alkalinity in old sand is constantly increasing, mainly Na_2CO_3 or NaHCO_3 Etc. Mixing the prepared sodium silicate sand at room temperature greatly reduces the binding capacity of the waterglass silicone between the sand and the sand, which is an isolated substance in sodium silicate sand and a kind of suction